Fresh air for the community

The history of half a millennium is being brought into the 21st century in a new, £3m state-of-art community facility in Gloucestershire.
The new Thornbury Community Centre, designed and commissioned by South Gloucestershire Council and built by Kier Western, features as a central element of its architecture, Passivent Airscoop DAD (Direct Air Dispersal) ventilation terminals. The six terminals, mounted on the roof ridge, provide effective natural ventilation of the whole building, in line with the Council’s policy of utilising sustainable strategies where possible, yet reflect the town’s traditional and historic architecture particularly the notable brick chimneys built in 1514 on the town’s castle, and other chimneys on buildings surrounding the new Centre on the site of the town’s former cattle market.

Project architects, The Property Consultancy, the Council’s in-house Property Services Division, worked with Passivent to achieve the bespoke design and appropriate ventilation/ air change rates of the Airscoop terminals and site them appropriately along the ridge to ensure each area of the Centre was efficiently ventilated, without the use of mechanical systems, thus saving electricity. As a result, each of the three teaching rooms features its own 1025mm x 1025mm Airscoop, with an additional two in the multi activity hall, and one above the café, providing a fresh air requirement in line with the existing CIBSE guidance of 8l/s/person.

Each Airscoop is linked to a Passivent control system, the only component which requires an electrical supply, which ensures the units operate whilst maintaining a comfortable internal ambient temperature.

Mike Houghton from The Property Consultancy, elaborates: “Thornbury is a traditional market town with many of the surrounding buildings featuring chimneys. The Passivent terminals are in keeping but with a modern environmental twist. We sited them on the ridge to further reflect the surroundings and deliberately enhance their role within the architecture and design. They are a worthwhile and prominent feature of the new building.”

David Stolton, Passivent Commercial Product Manager said: “The positioning on the ridge meant we designed the terminals specifically for the project, as the Airscoops are conventionally sited along the roof slope. Whilst the majority of the Centre roof is tiled, the section over the café is glazed to optimise light, providing a relaxing environment in the area. This however required further specific design work for the Airscoop, to ensure it was sited and fixed securely without risk of rain penetration.”

Passivent Airscoops work on wind power alone, using displacement principles to ventilate the space below. Air moving across the roof is scooped down chambers in the terminal into the room. The flow of new, cooler air pushes the internal, warmer air up and out through the Airscoop. Separate inlets/outlets within the Airscoop ensure the airflow is always separated regardless of wind direction. The DAD Airscoop was chosen as it provides excellent air distribution within the internal space due to the unique internal diffuser design, creating a circular air path within the space.

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